Gas purifying apparatus and semiconductor manufacturing apparatus

Abstract

A gas purifying apparatus for removing particles from a gas. The gas purifying apparatus includes a first filter layer and a second filter layer, and the diameter of a fiber forming the first filter layer is larger than that of a fiber forming the second filter layer. A semiconductor manufacturing apparatus can use such a gas purifying apparatus.

1 : A gas purifying apparatus for removing particles from a gas, comprising:
 a first filter layer and a second filter layer disposed upstream and downstream of a flow of the gas, respectively,   wherein the first filter layer captures particles which are smaller than particles captured by the second filter layer.   
   
   
       2 : The gas purifying apparatus of  claim 1 , wherein the diameter of a fiber forming the first filter layer is larger than the diameter of a fiber forming the second filter layer. 
   
   
       3 : The gas purifying apparatus of  claim 2 , wherein the particles have diameters no greater than about 50 nm and contain metal. 
   
   
       4 : The gas purifying apparatus of  claim 2 , wherein a pressure loss in the first filter layer is smaller than a pressure loss in the second filter layer. 
   
   
       5 : The gas purifying apparatus of  claim 1 , wherein the first filter layer is made up of a single layer or plural layers. 
   
   
       6 : The gas purifying apparatus of  claim 1 , wherein a material forming the first filter layer is selected from a group including metal, resin, ceramics and activated carbon, and a material forming the second filter layer is glass or resin. 
   
   
       7 : The gas purifying apparatus of  claim 1 , further comprising a filtration layer for eliminating an organic material or an ion from the gas. 
   
   
       8 . (canceled) 
   
   
       9 : A gas purifying apparatus for eliminating particles from a gas, comprising:
 a first filter layer; and   a second filter layer,   wherein the first and second filter layers have different characteristics of particle capturing efficiency depending on a diameter variation of the particles.   
   
   
       10 : A gas purifying apparatus for eliminating particles from a gas, comprising:
 a first filter layer; and   a second filter layer,   wherein the first and second filter layers have different particle capturing efficiencies for particles having a same diameter.